Extensible antenna



Nov. 17, 1959 J. WENDLING EXTENSIBLE ANTENNA Filed May l, 1958 ELECT2\CAI 2] INSU LA'T\DN ff. rl/ 1/2 qu LA-nou /4ELEGTQH2AL IN lUnited States Patent O 2,913,073 ExrENsmLn ANTENNA John Wendling, Fort Wayne, Ind., assigner to The Magnavox Company, Fort Wayne, Ind., a corporation Application May 1, 1958, Serial No. 732,247 9 claims. (ci. isa-26) This invention relates generally to extensible antennas for communication equipment, and in particular to telescoping, extensible, dipole antennas which canbe trlggered or released for movement to extended position.

For use with communication equipment, particularly that of the mobile type, it has become conventional to provide antennas capable of being stored in or folded into a housing having a length which -is considerably smaller than the extended length of the antenna. A copending application of Woodrow P. Kirby et al., Serial No. 677,603, led August l2, 1957, now Patent No. 2,866,198, issued December 23, 1958, entitled Telescoping Dipole Antenna, and assigned to the assignee of the present invention, discloses and claims an extensible d1- pole antenna which can be stored in a housing whose length is approximately one-fourth of the extended length of the antenna.

The present invention is a modied version of the antenna disclosed and claimed in the above identied copending application. The antenna assembly embodying the present invention incorporates a means for providing the force necessary to extend or erect the antenna, this force being held in check by a triggering means or releasable latch. The antenna assembly of the present invention thus may be distinguished from the device of the above-identified application in that the means for extending the antenna is incorporated within the antenna assembly. The device herein described finds particular use in providing the necessary antenna for marking buoys, and for such use the triggering means may be held in place by a water soluble member. Thus, upon release of a buoy into water, the W-ater soluble member releases the trigger, causing the antenna to erect or extend itself.

A further object is to provide an extensible antenna assembly which can be released to extended position upon subjection of the antenna assembly to predetermined ambient conditions, such as the presence of water or the existence of a predetermined temperature.

A further object of the present invention is to provide an extensible antenna which is spring biased into extended position, but is held in retracted position by a trigger mechanism which releases the'antenna for movement into extended position when the trigger mechanism -is immersed in water.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

Fig. l represents a side sectional view of an antenna embodying the present invention, the antenna being shown in extended position.

Fig. 2 represents a top plan view of the antenna in retracted position.

Fig. 3 is a sectional view taken generally along the line 3-3 of Fig. 2.

Fig. 4 is a sectional view of a portion of the `antenna taken generally along the line 4-4 of Fig. 2.

Referring initially to Figs. 2, 3 and 4, there is shown an elongated tubular housing having a closure member 11 at its outer end and a closure member 11a at its opposite end held in place by appropriately positioned screws 11b. An outer tube 14, formed of suitable electrical insulating material, is carried by a header member 13 slidably received within the housing. The outer tube 14 extends beyond the housing through an appropriate openn in the outer end 19 of the tube 14. A coupling member 21, having reduced end sections, and formed of suitable electrical insulating material, extends for a portion of its length within the outer end of the tube 18 and is rigidly secured thereto. The other reduced end of the coupling member accommodates and secures the convolutions of the tightly wound erection spring 22 which, as may be seen in Fig. 3, initially is stressed into a U-shape and received onto the reduced end of a second coupling member 23. The coupling member 23 is similar in conguration to the member 21, but is formed, however, of electrically conductive material. The opposite reduced end 23a of the member 23 is received within the central bore of a rod 24 and rigidly secured therein.

The rod 24 extends through the housing and is slidably received within an opening 26 in the header member 13.

A sleeve 27, formed of suitable insulating material, sur` rounds the upper section of the rod 24 and slidably extends through an appropriately lsized opening in the housing closure member 11. A snap washer 28, extending around a groove in the rod 24, serves to seat a compresy sion spring 29 which extends between the washer and a shoulder formed by an internal ange 31 on the sleeve 27. As shown 1n lFig. 3, with the antenna in retracted position, the sleeve will thus be urged outwardly on the rod, its

, position being established by engagement with the coils of the erecting springl 22.

From the foregoing it will be evident that the telescoped tubes 14 and 18 are accommodated within the housing in side-by-side relation to the rod 24, with the stressed resilient member, formed by the spring 22, providing an articulated joint between .the rod and the tube 18.

The means for providing the force necessary to extend the antenna from the housing is provided by a compression spring 30 which extends between the lower housing closure member 11a and the underside of the header member 13. As may best be seen in Fig. 4, a ilexible draw-cordor cable 32 is suitably anchored at 33 to the inner end of the tube 18 and is brought out through an appropriate opening 34 in the closed end 19 of the tubev 14 and is anchored at 36 to the upper housing closure member 11.

The antenna lead cable 41 enters the housing through an opening 42 in the closure member 11, extends through an opening in the member 13, and is accommodated within the central bore of the tube 18. As may best be seen in Fig. 3, the coupling member 21 has an opening therethrough accommodating the antenna lead cable which further extends through the spring 22 and is elec- -trically connected at 43 by soldering or other suitable means to the coupling member 23. It will be understood,

nected to coupling member 23 and the'outer conductor:

being connected as at 43a (Fig. l) to the tube 18. The

tube 1,8 and the rod 24 thus form the two insulated sections of the dipole antenna structure.

With the telescoping tubes and the rod 24 in retracted position, as shown in Fig. 3, the spring 30 will be compressed land will exert an upward force upon the header member 13. This upward force is held in check by means of a trigger mechanism now to be described. The outer end 'of the housing carries a collar 44, held in place by meansof a bolt 46. The collar supports a sidewardly extending tongue 47 provided with upstanding flanges 48. A Cotter pin 49, extending through the iianges 48, serves to pivotally support an upwardly-extending trigger 51 by means of spaced ears S2 carried by the trigger. As may best be seen in Fig. 3, with the tubes in retracted position the shank portion of the trigger extends generally parallel to the adjacent tube 18. When so positioned, an inwardly extending tongue 53 of trigger 51 is disposed in overlying relation to the outer end member 19 of the tube 14. A band or ring 54, encircling the trigger 5.1 and the adjacent end of the sleeve Z7, serves to hold the trigger in upright position, thus positioning the tongue S3 so as to hold the antenna in retracted position against the force exerted by spring 30. The band 54 may be formed of a gelatinous, water soluble material so that the band will rupture when subjected to sufiicient moisture to dissolve or partially dissolve it.

In operation, with the antenna sections in retracted position, as shown in Figs. 3 and 4, upon rupture of the releasing band 54;-, the spring 30 will expand, pushing the trigger mechanism to its released position of Fig. 1 and driving the header member 13 and tube 18 to the outer end of the housing i6, thereby extending or unsheathing the nested tubes from the housing. This movement of the member f3 will continue until it engages the inner face of the housing closure member 11, and during such movement, as the cord 32 slides over the end 19 of the tube 14, the tube 13 will be withdnawn from nested relation with the tube 14 and will concurrently withdraw the rod 24 from the opening 26 in the header 13 and outwardly of closure member 11. p

As the rod is freed from the closure member, the spring 22 will snap it into upright position above the tube 18, as shown in Fig. l. As the rod and tube assume a linear, end-abutting relation, the sleeve 27 will be moved by the spring 29 into a position spanning the gap between the opposed ends of the rod and tube and enclosing the spring 22, its position being established by engagement of the flange 31 with the central enlarged portion of the coupling member 23. As will be evident from Pig. l, the erection of the spring 22 and the subsquent enclosure thereof by sleeve 27 serves to make rigid or lock the joint between the rod and the tube as the rod is freed from the housing.

The trigger mechanism is described above as being released by rupture of the water soluble band, and it will be evident that this form of trigger release has particular utility where the antenna is incorporated into a marking buoy to be released into Water. It will be understood that by forming the band of a temperature sensitive material, the rupture of the band and the subsequent expansion of the antenna could take place upon the occurrence of some predetermined ambient temperature. It may be thus seen that the present invention provides an extensible antenna which incorporates a means for providing the force necessary to extend the antenna and provides a triggering mechanism for holding the extending force in check until the existence of some predetermined ambient condition.

The features and advantages herein referred to maybe retained in modified forms of the present invention. The scope of the invention is therefore to be limited only by the appended claims.

The invention claimed is:

l. A telescoping dipole antenna adapted to be actuated to `extended position comprising an elongated storage housing accommodating in nested relation an outer first tube and an inner second tube, cooperating stop means carried by the outer end of the first tube and the inner end of the second tube to prevent complete withdrawal of the second tube from said first tube, a header member carried by the inner end of the first tube cooperating with the housing to prevent complete withdrawal of the first tube therefrom, an elongated member accornmo dated within said housing in side-by-side relation to said tubes, connecting means comprising a stressed resilient member joining the adjacent ends of said second tube and said elongated member adapted to snap the tube and member into end-opposed relation upon freeing of the elongated member from said housing, a locking sleeve carried by said elongated member adjacent said connecting means, a spring extending between said sleeve and said elongated member for urging the sleeve into a position spanning said connecting means when said tube and said member assume end-opposed relation, means forrextending the antenna comprising a flexible cable attached to the inner end of said second tube and extending therethrough to be attached to said housing, a compression spring within said housing urging said tubes therefrom, a trigger member carried by said housing and extending into engagement with said first tube for retaining said tubes within said housing, and means for holding said trigger in said retaining engagement including a water soluble member, whereby upon rupture of said member said compression spring initially withdraws the nested tubes from said housing and thereafter withdraws said second tube from said first tube and frees said elongated member from said housing.

2. A telescoping antenna adapted to be actuated to extended position comprising an elongated storage housing accommodating in nested relation anpouter first tube and an ,inner second tube, cooperating stop means carried by the outer end of the first tube and the inner end of the second tube to prevent complete withdrawal of the second tube from said first tube, a header member carried by the inner end of the first tube cooperating with the housing to prevent complete withdrawal of the first tube therefrom, an elongaged member accommodated within said housing in side-by-side relation to said tubes, resilient connecting means joining the adjacent ends of said second tube and said elongated member adapted to snap the tube and member into end-opposed relation upon freeing of the elongated member from said housing, means for extending the antenna comprising a flexible cable attached to the inner end of said second tube and extending therethrough to be attached to said housing, a compression spring within said housing urging said tubes therefrom, a trigger member carried by said housing and extending into engagement with said first tube for retaining said tubes within said housing, and means for holding said trigger in said retaining engagement including an ambient condition responsive member, whereby upon response of said member to the existence of said ambient condition, said compression spring initially withdraws the nested tubes from said housing and thereafter withdraws said second tube from said first tube and frees said elongated member from said housing.

3. A telescoping antenna adapted to be actuated to extended position comprising an elongated storage housing accommodating in nested relation an outer first tube and an inner second tube, cooperating stop means carried by the outer end of the first tube and the inner end of said second tube to prevent complete withdrawal of the second tube from said rst tube, a header member carried by the inner end of the first tube cooperating with the housing to prevent complete withdrawal of the first tube therefrom, an elongated member accommodated within said housing in side-by-side relation to said tubes, resilient connecting means joining the adjacent ends of said second tube and said elongated member adapted to snap the tube and member into end-opposed relation upon freeing of the elongated member from said housing, means for extending the antenna including biasing means within said housing urging said tubes therefrom, a trigger member carried by said housing and extending into engagement with said iirst tube for retaining said tubes within said housing, and means for holding said trigger in said retaining engagement, whereby upon release of said last-mentioned means said biasing means initially withdraws the nested tubes from said housing and thereafter withdraws said second tube from said first tube and frees said elongated member from said housing.

4. A multi-section dipole antenna extensible from a housing, said antenna including two nested tubes and a rod accommodated side-by-side within the housing, an articulated joint between the adjacent ends of said inner tube and said rod, said joint being biased to position said rod and said inner tube in end-opposed relation upon freeing of the rod from said housing a compression spring within said housing urging said tubes and said rod from said housing, a trigger member carried by the housing and cooperating with said nested tubes to retain said tubes and said rod within the housing against the force exerted by said compression spring, and means including a water soluble member for releasing said trigger to free said tubes and said rod from the housing, whereby said antenna is extended upon water immersion of said member.

5. A multi-section antenna extensible from a housing, said antenna including two nested tubes and a rod accommodated. side-by-side within the housing, an articulated joint between the adjacent ends of said inner tube and said rod, said joint being biased to position said rod and said inner tube in end-opposed relation upon freeing of the rod from said housing, biasing means within said housing urging said tubes and said rod from said housing, a trigger member carried by the housing and cooperating with said nested tubes to retain said tubes and said rod within the housing against the force exerted by said biasing means, and means including a water soluble member for releasing said trigger to free said tubes and said rod from the housing, whereby said antenna is extended upon Water immersion of said member.

6. A multi-section antenna extensible from a housing, said antenna including two nested tubes and a rod accommodated side-by-side within the housing, an articulated joint between the adjacent ends of said inner tube and said rod, said joint being biased to position said rod and said inner tube in end-opposed relation upon freeing of the rod from said housing, biasing means within said housing urging said tubes and said rod from said housing, a trigger member carried by the housing and cooperating with said nested tubes to retain said tubes and said rod within the housing against the force exerted by said biasing means, and means responsive to a predetermined ambient condition for releasing said trigger to permit extension of said antenna by said biasing means.

7. A multi-section dipole antenna extensible from a housing, said antenna including two nested tubes and a rod accommodated side-by-side within the housing, an articulated joint between the adjacent ends of said inner tube and said rod, said joint being biased to position 'said rod and the inner tube in end-opposed relation upon freeing of the rod from said housing, and means for extending said tubes and freeing said rod from said housing including a compression spring anchored on said housing and urging said tubes and said rod therefrom, and a retaining member carried by said housing and cooperating with said tubes for preventing their withdrawal from said housing, said retaining member being adapted to be released upon the occurrence of a predetermined condition to thereby permit extension of said antenna by said spring.

8. A multi-section antenna extensible from a housing, said antenna including two nested tubes and a rod accommodated side-by-side within the`V housing, anarticulated joint between the adjacent ends of said inner tube and said rod, said joint being biased to position said rod and the inner tube in end-opposed relation upon freeing of the rod from said housing, and means for extending said'tubes and freeingsaid rod from said housing including a compression spring anchored on said housing and urging said tubes and said rod therefrom, and a member carried by said housing and cooperating with said tubesl for releasing said spring.

9. A multi-section antenna extensible from a housing, said antenna including two nested tubes and a rod accommodated side-by-side within the housing, an articu lated joint between the adjacent ends of said inner tube and said rod, said joint being biased to position said rod and the inner tube in end-opposed relation upon freeing of the rod from said housing, and means including a compression spring extensible within said housing for urging said tubes and said rod therefrom.

References Cited in the le of this patent UNITED STATES PATENTS 2,402,143 Arenstein June 18, 1946 2,470,783 Mead May 24,l 1949 2,593,432 Freas Apr. 22, 1952. 

